Although the face of the wall in either case may be strictly perpendicular, it is
better that each layer should recede a bit. Construct it after the manner of the rock garden, laying the stones so that the top will be level, or approximately so.
Dry wall for retaining bank. Cross-section, showing crevices, soil runs and tilting of rocks
In planting also, follow the same rules. It is better to plant as the work progresses. Either plants or seed may be used. If it is seed, press carefully into the soil in the front of the crevices. Small seed may be mixed in thin mud and this plastered on the soil. For a tiny crevice make a pill of the mixture.
Double-faced dry wall. A few rocks are used with the soil filling and here and there one on top of it
The range of reliable plants that do not call for special care is not great so far as the crevices are concerned. All the stonecrops, the house leeks, Arabis albida, red valerian (Centranthus ruber), aubrietia, Alyssum saxatile, snapdragon, wallflower (Cheiranthus Cheiri), Kenilworth ivy, Viola tricolor, Dianthus plumarius, and Dianthus deltoides are all very ser